The heparan sulfate sulfotransferase 3-OST3A (HS3ST3A) is a novel tumor regulator and a prognostic marker in breast cancer.

Heparan sulfate (HS) proteoglycan chains are key components of the breast tumor microenvironment that critically influence the behavior of cancer cells. It is established that abnormal synthesis and processing of HS play a prominent role in tumorigenesis, albeit mechanisms remain mostly obscure. HS function is mainly controlled by sulfotransferases, and here we report a novel cellular and pathophysiological significance for the 3-O-sulfotransferase 3-OST3A (HS3ST3A), catalyzing the final maturation step of HS, in breast cancer. We show that 3-OST3A is epigenetically repressed in all breast cancer cell lines of a panel representative of distinct molecular subgroups, except in human epidermal growth factor receptor 2-positive (HER2+) sloan-kettering breast cancer (SKBR3) cells. Epigenetic mechanisms involved both DNA methylation and histone modifications, producing different repressive chromatin environments depending on the cell molecular signature. Gain and loss of function experiments by cDNA and siRNA transfection revealed profound effects of 3-OST3A expression on cell behavior including apoptosis, proliferation, response to trastuzumab in vitro and tumor growth in xenografted mice. 3-OST3A exerted dual activities acting as tumor-suppressor in lumA-michigan cancer foundation (MCF)-7 and triple negative-MD Anderson (MDA) metastatic breast (MB)-231 cells, or as an oncogenic factor in HER2+-SKBR3 cells. Mechanistically, fluorescence-resonance energy transfer-fluorescence-lifetime imaging microscopy experiments indicated that the effects of 3-OST3A in MCF-7 cells were mediated by altered interactions between HS and fibroblast growth factor-7 (FGF-7). Further, this interplay between HS and FGF-7 modulated downstream ERK, AKT and p38 cascades, suggesting that altering 3-O-sulfation affects FGFR2IIIb-mediated signaling. Corroborating our cellular data, a clinical study conducted in a cohort of breast cancer patients uncovered that, in HER2+ patients, high level expression of 3-OST3A in tumors was associated with reduced relapse-free survival. Our findings define 3-OST3A as a novel regulator of breast cancer pathogenicity, displaying tumor-suppressive or oncogenic activities in a cell- and tumor-dependent context, and demonstrate the clinical value of the HS-O-sulfotransferase 3-OST3A as a prognostic marker in HER2+ patients.

Prevalence of Barrett's esophagus in systemic sclerosis.

OBJECTIVE: The esophagus is the most commonly affected gastrointestinal area in systemic sclerosis (SSc). Patients with SSc frequently develop gastroesophageal reflux, esophageal injury, and sometimes, intestinal metaplasia, or Barrett's esophagus (BE), which may increase the risk of esophageal adenocarcinoma. This study sought to determine the prevalence of BE and esophageal adenocarcinoma in a cohort of SSc patients. METHODS: One hundred ten SSc patients who were receiving long-term treatment with proton-pump inhibitors (PPIs) were assessed systematically by esophageal manometry and endoscopy. Esophageal biopsies were performed when macroscopic abnormalities were detected, and BE was diagnosed histologically. RESULTS: Among the 110 patients, 14 had BE (12.7%). None of the patients with BE had adenocarcinoma, but 3 of the 14 patients (21%) had dysplasia on esophageal biopsy. Similar proportions of patients with and without BE had abnormal peristalsis and decreased lower esophageal sphincter pressure. No association between BE and other disease characteristics was demonstrated. CONCLUSION: In this study, 12.7% of SSc patients who had been treated with PPIs for long periods had BE, similar to the prevalence in patients with gastroesophageal reflux disease. Although none of the patients had esophageal adenocarcinoma, patients with BE should be followed up closely, particularly patients with dysplasic BE. Long-term prospective studies are warranted to determine the phenotype of SSc patients at high risk of developing dysplasia or esophageal adenocarcinoma.

Cartilage formation in growth plate and arteries: from physiology to pathology.

Vascular calcifications are the consequence of several pathological conditions such as atherosclerosis, diabetes, hypercholesterolemia and chronic renal insufficiency. They are associated with risks of amputation, ischemic heart disease, stroke and increased mortality. A growing body of evidence indicates that vascular smooth muscle cells (VSMCs) undergo chondrogenic commitment eventually leading to vascular calcification, by mechanisms similar to those governing ossification in the cartilage growth plate. Our knowledge of the formation of cartilage growth plate can therefore help us to understand why and how arteries calcify and, consequently, develop new therapeutic strategies. Reciprocally, thorough consideration of the events leading to ectopic chondrocyte differentiation appears crucial to further increase our understanding of growth plate formation. In this context, we will review the effects of known or suspected factors that promote chondrogenic differentiation in growth plate and arteries.

[Diclofenac-induced colitis complicated by Klebsiella oxytoca infection]. / Colite induite par le diclofénac et compliquée d'une infection à Klebsiella oxytoca.

A 25-year-old man presented with abdominal pain and bloody diarrhea. Colonoscopy showed hemorrhagic proctocolitis with superficial erosions. Histology was consistent with the diagnosis of ulcerative colitis and biopsy cultures were negative. Despite treatment with prednisolone (40 mg/day), his clinical condition deteriorated and he was referred to our institution. On repeated questioning, the patient reported self-medication with diclofenac (200 mg/day) for 6 weeks to treat tendinitis prior to the beginning of digestive symptoms. Rectosigmoidoscopy confirmed bleeding colitis and repeated biopsy cultures showed Klebsiella oxytoca. Corticosteroids were stopped and ofloxacin (400 mg/day) was prescribed for 14 days. Diarrhea quickly resolved. Colonoscopy 8 weeks later showed only patchy erythematous mucosa without bleeding or erosions. Two years later, the patient remains asymptomatic with normal total colonoscopy. The definitive diagnosis was de novo NSAID-induced colitis subsequently complicated by Klebsiella oxytoca infection.

Endothelial cell prostacyclin synthesis induced by lymphocytes is independent of the membrane fatty acid composition of both cell types and of E-selectin, VCAM-1 or ICAM-1-mediated adhesion.

Prostacyclin (PGI2), the main prostanoid in most vascular tissues regulates haemostasis and vascular tone, as well as the proliferation of smooth muscle cells. We have previously reported that lymphocyte contact with endothelium enhances endothelial cell PGI2 output. Here, we demonstrate the specificity of lymphocytes for switching on this response. Co-incubation of human umbilical vein endothelial cells (HUVEC) in serum-free medium with allogeneic peripheral blood lymphocytes (PBL), at a PBL:HUVEC ratio of 9:1, enhanced the basal (HUVEC alone) PGI2 output by 2.5-fold under static conditions, and was not altered in conditions mimicking shear stress. It occurred without previous activation of either cell type and was dependent upon specific interactions with PBL. Indeed, the PGI2 output induced by the co-incubation with resting neutrophils, non-activated platelets or latex beads was significantly lower than that induced by PBL. Blocking endothelial cell adhesion molecules (ECAM) E-selectin, vascular cell adhesion molecule-1 (VCAM-1) or intracellular adhesion molecule-1(ICAM-1) did not modify the PBL-induced PGI2 output, although 51Cr-labelled PBL adhesion was significantly decreased with anti-ICAM-1 antibody. Changes in the fatty acid composition of membrane phospholipids induced by incubation with eicosapentaenoic (EPA) or docosahexaenoic acids (DHA) resulted in diminished basal PGI2 output and adhesion of 51Cr-labelled PBL, whereas the PBL-stimulated PGI2 output was not modified. This specific cell-cell interaction represents a new stimulus for PGI2 synthesis that does not primarily involve the ECAM pathway, is independent of cell membrane fatty acid composition and shear stress. This switch-on for PGI2 synthesis, which is induced by lymphocytes, might serve as a protection against atherogenesis.

Human lymphocytes stimulate prostacyclin synthesis in human umbilical vein endothelial cells. Involvement of endothelial cPLA2.

Prostacyclin (PGI2) contributes to the maintenance of a nonadhesive luminal surface in blood vessels due to its anti-platelet and vasodilatory properties. Here, we sought to determine whether peripheral blood lymphocytes (PBL) may regulate the PGI2 production of human umbilical vein endothelial cells (HUVEC). Cell-cell contact between HUVEC and lymphocytes markedly enhanced PGI2 synthesis as a function of the number of lymphocytes added. This stimulated synthesis was totally suppressed when lymphocytes and HUVEC were separated by a microporous insert. It was not due to prostaglandin H synthase up-regulation. The pretreatment of lymphocytes with the PGI2 synthase inhibitor tranylcypromine partially inhibited PGI2 synthesis (47%), suggesting a transcellular metabolism of the endothelial prostaglandin endoperoxide PGH2 by the lymphocyte PGI2 synthase. Experiments using [14C]arachidonate-labeled lymphocytes coincubated with unlabeled HUVEC, and [14C]arachidonate-labeled HUVEC coincubated with unlabeled lymphocytes showed that the arachidonic acid used for PGI2 synthesis was totally of endothelial origin. Furthermore, the PGI2 synthesis was strongly inhibited by the cytosolic phospholipase A2 inhibitor, MAFP and totally suppressed by the combination of the calcium chelators, BAPTA and EGTA. Collectively, these results suggest that lymphocytes trigger an outside-in signaling in endothelial cells involving cPLA2 activation. Overall, the switch-on for PGI2 synthesis induced by lymphocytes might serve as a protection against atherothrombogenesis.

[Acute quinine poisoning treated with high dose of diazepam]. / Intoxication aiguë à la quinine traitée par diazépam à forte dose.

BACKGROUND: High concentrations of quinine, the drug of choice for severe malaria, are toxic to the cardiovascular system, producing hypotension and abnormal myocardial conduction. CASE REPORT: An 8 year-old girl was admitted for fever, headache and arthralgias. Examination of a thick film of blood showed Plasmodium falciparum (parasitemia: 2%). She was given quinine intravenously. Ventricular tachycardia (150/min) and status epilepticus were seen 48 hours later, necessitating ventilatory support, plasma volume expander and IV sodium thiopental. On admission to an intensive care unit, the patient had hypothermia, was comatose (stage IV) with a reactive mydriasis and bradycardia (30/min). ECG confirmed bradycardia and showed a widened QRS complex. There was also a bilateral retinal edema. The blood level of quinine was 61 mumol/liter (therapeutic levels: 6-15). Retrospective inquiry revealed that the quinine initially administered had been incorrectly diluted. The child was treated with furosemide and adrenaline, followed by dobutamine and albumin infusion. She was then given diazepam (initial dose: 2 mg/kg then 6 mg/kg/day divided into 4 doses) intravenously, plus lidocaine, methylprednisolone and glycerol. The sinusal rhythm became normal 1 hour after the first bolus of diazepam. Consciousness gradually improved over the 10 days after admission while treatment was progressively discontinued. There were no sequelae, except for a transitory bilateral blindness. CONCLUSION: The cardiovascular side-effects of quinine poisoning can be reversed with diazepam, as has previously been reported in cases of chloroquine poisoning.